Regulation of liquid fuel injection pumps



June 12, 1951 w. E. w. NICOLLS ,77

REGULATION OF LIQUID FUEL INJECTION PUMPS Filed Nov. 7, 1950 2 Shee't-Sheet 1 HE'MNLCOLZ JW/ZMW June 12, 1951 w. E. w. NICOLLS REGULATION OF LIQUID FUEL INJECTION PUMPS 2 Sheets-Sheet 2 Filed Nov. 7, 1950 Inventor ,E.]$[Nl /(LolL6 0 Patented June 12, 1951 Wilfrid Ed war-d Walter Nico'lls, Pimrer, England;

assignor to (3. A-. V. Limited; London, England Application November 7, 1950, Serial No; 1943406 In Great" Britain August 2 1, 1948 2 Claims.

This invention relates to liquid fuel injectionpumps for use with internal combustion engines;- and of the kind having; combined therewith means for automatically varying the pump output in response todifferent speed. conditions. When starting an: engine it is usually. desirabletdsupply the. fuel inlexcessof the normal-maxi.- mumamount, and the object-of the present invention is toprovide improved means for satisfying this requirement The. invention comprises the combination with the-governing means of the pump, of a spindle angularly operable by an attendant, an arm in fixed relation to the: spindle and adapted to cooperate with the governing means, a second arm forming a two-part stop'and freely mounted on the spindle, a spring device. for interconnecting the stop arm with the spindle, apspring; acting; on the stop arm, and. an abutmentmovable by the governing means andadapted toco-operate with the-stop arm.

In the accompanying drawings:

Figure 1 isa part-sectional 'sideelevation illustrating an: application of the invention to: a known form of centrifugally actuated fuel pump regulating means, and Figure 2 is a similar view to Figure 1, illustrating an application of the invention to a fuel pump regulating means which is actuated pneumatically in response to variations in the air induction manifold of the engine.

Figures 3 and 4 are part sectional side elevations illustrating, in difierent working conditions, the mechanism forming the subject of the present invention, and

Figure 5 is a sectional plan of the mechanism.

Referring to Figure 1, a well known form of reciprocatory fuel injection pump has combined with it a slidable bar a for actuating the delivery regulating means of the pump, and in association with the rotary driving spindle of the pump is arranged a centrifugal governor b. The latter is connected to the bar a by a lever c which is also operable by a lever it under the control of the attendant. Variations in the speed of the engine result in longitudinal movements of the bar by the governor for varying the quantity of fuel discharged to the engine in each stroke of the pump. An alternative known means for actuating the bar a is shown in Figure 2, where the said bar is connected to a diaphragm e loaded by a spring f. The chamber 9 at one side of the diaphragm is adapted for connection to the air induction manifold of the engine, and variations of pressure in the mani- 2v fold: are accompanied by corresponding movements: ot the bard;

In applying the present invention to either of the forms: of" governing means above described; there' is providedia spindle h which is a-ngula-rly movable by: the attendant through; a lever ii (Figure: 5) orsecured an arm which at its outer endcan bear on' one side of: a lateral; peg k or other lateral: projection: on the' sliiiablebar a; for err-- ablingthe: attendant to, move the bar to the positioni'n'which thesupplyoffuel by the pump is stopped. On-the said spindle is also freely mounted. an? arm m which at' its outer end is connectech bya link n t0fa'loading spring, 0. The

other (androunded end) issstepped to form two: stop parts p;.q. with: which can: cot-operate an ad justable abutment- 1' connected; to.- the slidable bar a;

For interconnecting: the spindle and the stop armm; therspindie iszformedwith a; longitudinal groove. 8 in WhiChiliSfi :bIa-de spring; 15 (Figure: 5) and in the bore of the arm is formed a groovew with: which: the spring blade can; engage" for securing the arm m to the spindle. Also in the arm is formed adjacent to the step between the stop parts 21, q, a radial hole through which extends a pin 1), the inner (and headed) end of which is supported on the blade spring and the outer end of which is operable by the abutment r on the arm connected to the slidable bar.

The lever i and arm 7' are loaded by a coiled spring 11; which at one end bears on the arm 7' and which at the other end is anchored to a stop 3 on the housing, the spring serving to hold the lever i and arm 7' in their rest position.

The mode of action of the mechanism is as follows:

To bring the engine to rest, the attendant operates the lever i above mentioned against the action of the spring 10 for moving the slidable bar a (through the medium of the arm a) to the limit position in which the bar 0, effects interruption of the supply of fuel by the pump as shown in Figure 3, the stop arm m being meanwhile held by the spring 0. In this position the blade spring 13 is able to enter the groove u in the stop arm m which is thereby connected to the spindle h. Also in this position the stop part 17 which determines the normal maximum fuel supply lies in line with the abutment. After the engine has come to rest the attendant releases the lever z, and the spring w then returns the lever 2' and the arm 7' to their initial position thereby causing the stop arm m to take up the position shown (Dn' this spindle" is formed:

in Figure 4, which is limited by the engagement of a projection 2 on the arm 7' against the fixed stop 3. In this movement the stop arm m moves with the spindle h against the action of the spring 0. The other part q of the stop then lies opposite the abutment r as shown in Figure 4, and allows the bar a to be moved to the position in which the pump can supply the required excess fuel. When the abutment 1' comes into contact with the pin it depresses the latter and so disengages the blade spring t from the stop arm m, but movement of this arm by its loading spring 0 is prevented by contact of the abutment r with the shoulder between the parts p, q of the stop arm. When the engine is started on the next occasion the required excess fuel is thus automatically provided and as soon as the engine gains speed the pump governing mechanism moves the bar a (to the right) towards its reduced fuel position, thereby disengaging the abutment r from the shoulder on the stop arm and allowing the spring 0 connected to the stop arm to move this arm to the position in which the part 10 of the stop which determines the normal maximum supply is opposite the abutment r as shown in Figure 1. Thereafter the variation of pump output with varying load conditions proceeds in the usual manner. To stop the engine the driver returns the slidable bar to its limit position and in so doing the blade spring t re-engages the stop arm with the spindle in readiness for the next starting operation.

The above description applies equally to the alternative governing means shown in Figure 2.

By this invention the adaptation of the pump control mechanism to provide the required extra fuel when starting the engine is effected in a very simple and satisfactory manner. The invention is, however, not restricted to the example above described, as subordinate details may be modified to suit different requirements.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. For use with a liquid fuel injection pump of the kind specified, means for enabling a quantity of fuel to be supplied to an engine in excess of the normal maximum when starting the engine, the said means comprising the combination with the governing means of the pump, of a spindle angularly operable by an attendant, an arm in fixed relation to the spindle and adapted to cooperate with the governing means, a second arm forming a two-part stop and freely mounted on the spindle, a spring device for interconnecting the stop arm with the spindle, a spring acting on the stop arm, and an abutment movable by the governing means and adapted to co-operate with the stop arm.

2. Means as and for the purpose claimed in claim 1, and comprising the combination of a longitudinally grooved spindle operable by an attendant, an arm in fixed relation to the spindle and adapted to co-operate with the governing means, an internally grooved stop arm freely mounted on the spindle and having a stepped and rounded end providing two stop parts, a spring blade located in the groove of the spindle and adapted to engage the groove in the stop arm, a radially movable pin extending through the stop arm and adapted to disengage the spring blade from the stop arm, a spring acting on the stop arm, and an abutment movable by the governing means, the said abutment being adapted to act on the pin disengaging the spring blade and to co-operate with the stepped ends of the stop arm for determining the normal and excess maximum fuel supply.

WILFRID EDWARD WALTER NICOLLS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,974,851 Hurst Sept. 25, 1934 2,331,577 Sonntag Oct. 12, 1943 2,520,856 Schowalter Aug. 29, 1950 

